Add-on modules

Add-on modules for increasing system availability

A power supply unit on its own cannot guarantee fault-free 24 V supply. Power failures, extreme line voltage fluctuations, or a faulty load can disrupt plant operation and result in high costs. The add-on modules offer everything from extensive protection against interference on the primary and secondary side right up to complete all-round protection.

Redundancy modules – for doubling system availability

SITOP redundancy modules

The redundancy module decouples two power supplies of the same type so that the loads are still supplied by the second power supply (1 + 1 redundancy) in case one of the two power supplies fails.

Redundancy modules support parallel connected power supplies of the same type to increase power while offering redundancy at the same time (N + 1 redundancy).

You can use the redundancy module NEC Class 2 to implement a redundant 24 V supply limited to an output power of 100 VA.

Selectivity modules – for protection of 24 V and 48 V feeders

SITOP selectivity modules

The selectivity module is used in conjunction with 24 V and 48 V power supplies to distribute the load current over multiple feeders and to monitor the individual partial currents. Faults caused by overload or short-circuits in individual branches are detected and selectively switched off so that the remaining load current paths remain unaffected. This achieves fast fault diagnostics and minimizes downtimes.

Buffer module – bridging power failures for as long as seconds

SITOP buffer modules

Power failures normally only last for fractions of a second, but they can still cause costly and time-consuming damage in sensitive production areas. In combination with SITOP 24 V power supply units, the buffer module bridges short voltage dips of this type with its electrolytic capacitors and ensures uninterrupted operation.

Inrush current limiter – for protection of downstream power supplies against excessively high inrush currents

SITOP inrush current limiters are used to reliably reduce the starting currents that are caused, for example, by transformers or with pulse-controlled power supplies by the rectifier circuit on the input side with capacitor charging.

However, they can also be used as a fuse for relay outputs downstream from the power supply in order to ensure the functionality of these relay modules when high inrush currents are connected to these loads.

Select the appropriate add-on modules quickly and easily with the TIA Selection Tool:

http://www.siemens.com/tst